46 Table 4.5 shows some properties of asphalt concrete modified with crumb rubber 2.5.
Through the review of the Marshall Properties test results in Table 4.4 were obtained the following observations that the OBC when added crumb rubber 2.5 is
6.475 bitumen, that is shown in Figure 4.15
4.14.2. Properties of Asphalt Concrete With 5.0 Crumb Rubber.
Table 4.6. Properties of asphalt concrete with 5.0 crumb rubber 6070 Asphalt
content Stabilities
Kg Flow
mm VFWA
Air void MQ
Density VMA
5.0 784.31
4.00 54.60
8.96 195.81
2.24 19.72
5.5 883.42
4.13 59.63
8.04 214.10
2.24 19.91
6.0 962.00
3.97 65.84
6.82 242.08
2.26 19.85
6.5 921.08
3.60 70.68
5.98 256.75
2.26 20.13
7.0 846.48
2.80 73.37
5.53 304.59
2.26 20.73
This relationship between the stability and the asphalt content with CR 5.0 is shown in Figure 4.16
Figure 4.16. Correlation stability and AC with 5.0 CR toward asphalt content
y = -218,51x
2
+ 2603,2x - 6777,3 R² = 0,9855
400 500
600 700
800 900
1000 1100
4,5 5,0
5,5 6,0
6,5 7,0
7,5
Sta bil
it a
s k
g
Asphalt Content
5.0 CR Series2
min 800 Series3
Poly. 5.0 CR
47 Through the review of the stability test results in Table 4.5 and Figure 4.16 were
obtained the following observations that the stability value of asphalt concrete with crumb rubber 5.0 is highest with asphalt content 6.0 by 982.68 kg and is smallest
with asphalt content 7.0 by 732.02 with add the 2.5 crumb rubber effect at the cohesion and the bonding stability of modified bitumen decrease. So the stability value of
asphalt concrete modified without crumb rubber is higher than asphalt concert with crumb rubber, and the stability value of asphalt concrete modified with crumb rubber
2.5 is higher than asphalt concert with crumb rubber 5.0 but the stability increases along with the decrease of CR content up to a certain extent optimum and decreases
after it passes the optimum limit. This happens because the asphalt as the binding material between the aggregate can become a lubricant after the optimum limit as the
binding.
This relationship between the flows and the asphalt content is shown in Figure 4.17.
Figure 4.17. Correlation flows and AC with 5.0 CR toward asphalt content Through the review of the flow test results in Table 4.6. and Figure 4.17. the
following observations were obtained that flow value of asphalt concrete with crumb rubber 5.0 is highest with asphalt content 5.5 by 4.13 mm and smallest with asphalt
content 7.0 by 2.8 mm. Thus it can be concluded that the higher the asphalt content
y = -0,6571x
2
+ 7,3457x - 16,462 R² = 0,9855
0,00 1,00
2,00 3,00
4,00 5,00
6,00
4,5 5,0
5,5 6,0
6,5 7,0
7,5 8,0
F lo
w m
m
Asphalt Content
5.0 CR Series2
min 3 Series3
Poly. 5.0 CR
48 increases flow. With the addition of the asphalt content will affect the mixes become less
flexible and the resistance to deformation decreases resulting in a high flow value.
This relationship between the marshal quotients and the asphalt content with CR 5.0 is shown in Figure 4.18
Figure 4.18. Correlation MQ and AC with 5.0 CR toward asphalt content Through the review of the Marshall quotient test results in Table 4.6 and Figure
4.18 were obtained the following observations that Marshall Quotient value of asphalt concrete with crumb rubber 5.0 is highest with the 6.5 by 256.75 mm and smallest
with asphalt content 5.0 by 195.81 mm. Thus it can be concluded that the 5.0 CR with bitumen increases Marshall Quotient
.
This relationship between the air void and the asphalt content with CR 5.0 is shown in figure 4.19
y = 33,134x + 43,573 R² = 0,8911
100 150
200 250
300 350
4,5 5,0
5,5 6,0
6,5 7,0
7,5 M
Q
Asphalt Content
5.0 CR Series3
Series4 Series5
Linear 5.0 CR
49 Figure 4.19. Correlation Air Void and AC with 5.0 CR toward asphalt content
Through the review of the air void test results in Table 4.6 and Figure 4.19 were obtained the following observations that air void value of asphalt concrete with crumb
rubber 5.0 is highest with the 5.0 by 8.96 and smallest with asphalt content 7.0 by 5.53. Thus it can be concluded that the 5.0 CR with bitumen decreases air void.
This relationship between the VFWA and the asphalt content is shown in Figure 4.20 F
i g
u r
e
4 .
2
: Correlation VFWA and AC with 5.0 CR toward asphalt content Through the review of the VFWA results in Table 4.6 and Figure 4.20 were
obtained the following observations that VFWA value of asphalt concrete with crumb
y = -1,7809x + 17,751 R² = 0,9785
2,00 3,00
4,00 5,00
6,00 7,00
8,00 9,00
10,00
4,5 5,0
5,5 6,0
6,5 7,0
7,5
A ir
V o
id
Asphalt Content
5.0 CR Series4
Series5 Linear 5.0 CR
y = 9,7158x + 6,5298 R² = 0,9843
40,00 45,00
50,00 55,00
60,00 65,00
70,00 75,00
80,00
4,5 5
5,5 6
6,5 7
7,5 VF
WA
Asphalt Contente
Series3 5.0 CR
min 65
50 rubber 5.0 is highest with the 7.0 by 73.37 and smallest with asphalt content 5.0
by 54.60. Thus it can be concluded that the 5.0 CR with bitumen increases VFWA. This relationship between the VMA and the asphalt content with CR 5.0 is shown in
figure 4.21
Figure 4.21. Correlation VMA and AC with 5.0 CR toward asphalt content Through the review of the VMA results in Table 4.5 and Figure 4.21 were
obtained the following observations that VMA value of asphalt concrete with crumb rubber 5.0 is highest with the 7.0 by 20.73 and smallest with asphalt content 5.0
by 19.72. Thus it can be concluded that the 5.0 CR with bitumen increases void mine aggregate.
y = 0,4473x + 17,383 R² = 0,7911
12,00 14,00
16,00 18,00
20,00 22,00
24,00
4,50 5,00
5,50 6,00
6,50 7,00
7,50 VM
A
Asphalt Content
Series4 5.0 CR
51 Figure 4.22. Correlation Marshall Properties toward 5.0 CR
Through the review of the Marshall Properties test results in Table 4.6 were obtained the following observations that the optimum bitumen content when added
crumb rubber 5.0 is 6.45 bitumen, that is shows in Figure 4.22
4.14.3. Properties of Asphalt Concrete With 5.0 Crumb Rubber.
